Home directories

I’m having a problem at school that is a bit annoying. The nethomes server will randomly delete a user’s home directory after awhile. I can’t really pin point when or why it’s doing this. It is semi random. It’s not a lot of users, but enough that it’s a pain in my ass. I do backup the home directories nightly, but it still sucks. Been chasing this down for awhile now and can’t seem to find the cause.